Arizona authorities are trying to find out who is responsible for 11 shooting incidents on a Phoenix freeway in two weeks. (Image: NBC News screenshot)

Arizona police have taken into custody a man and woman in connection with two weeks of shootings along a Phoenix highway. Only the man has been detained for further questioning.

Public Safety vehicles zeroed in on a silver Tahoe in a complex parking on Friday before taking the couple in for questioning, a local ABC affiliate reported.

Witnesses said police appeared to be waiting for the man to return to his parked vehicle and, when he did, moved in quickly, surrounding his SUV with unmarked vehicles.

“What you saw occur today is a result of a lot of troopers on the road, a lot of detectives on the road, a lot of undercover and marked vehicles, just a lot of work by our detectives trying to solve this case,” Arizona Department of Public Safety spokesman Bart Graves said.

Residents along Interstate 10 have experienced 11 shooting incidents since Aug. 29, prompting authorities to offer a $20,000 reward for information leading to the suspects’ arrest.

Col. Frank Milstead, director of the state’s Department of Public Safety, said earlier in the week he believed there was more than one shooter.

“I am of the opinion right now that we have multiple shooters just because the M.O.’s have changed,” Col. Milstead said Thursday, NBC reported.

Since the shootings began, one teenager girl was injured by shattered glass and a bus driver had a round streak into his vehicle and lodge into a seat. Other drivers have had windshields shattered and body damage to their vehicles.